/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * -----------------------------
 * StandardEntityCollection.java
 * -----------------------------
 * (C) Copyright 2001-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 23-May-2002 : Version 1 (DG);
 * 26-Jun-2002 : Added iterator() method (DG);
 * 03-Oct-2002 : Fixed errors reported by Checkstyle (DG);
 * 19-May-2004 : Implemented Serializable (DG);
 * 29-Sep-2004 : Renamed addEntity() --> add() and addEntities()
 *               --> addAll() (DG);
 * 19-Jan-2005 : Changed storage from Collection --> List (DG);
 * 20-May-2005 : Fixed bug 1113521 - inefficiency in getEntity() method (DG);
 * ------------- JFREECHART 1.0.x ---------------------------------------------
 * 01-Dec-2006 : Implemented PublicCloneable and fixed clone() method (DG);
 *
 */

package net.droidsolutions.droidcharts.core.entity;

import java.io.Serializable;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

/**
 * A standard implementation of the {@link EntityCollection} interface.
 */
public class StandardEntityCollection implements EntityCollection, Cloneable,
		Serializable {

	/** For serialization. */
	private static final long serialVersionUID = 5384773031184897047L;

	/** Storage for the entities. */
	private List entities;

	/**
	 * Constructs a new entity collection (initially empty).
	 */
	public StandardEntityCollection() {
		this.entities = new java.util.ArrayList();
	}

	/**
	 * Returns the number of entities in the collection.
	 * 
	 * @return The entity count.
	 */
	public int getEntityCount() {
		return this.entities.size();
	}

	/**
	 * Returns a chart entity from the collection.
	 * 
	 * @param index
	 *            the entity index.
	 * 
	 * @return The entity.
	 * 
	 * @see #add(ChartEntity)
	 */
	public ChartEntity getEntity(int index) {
		return (ChartEntity) this.entities.get(index);
	}

	/**
	 * Clears all the entities from the collection.
	 */
	public void clear() {
		this.entities.clear();
	}

	/**
	 * Adds an entity to the collection.
	 * 
	 * @param entity
	 *            the entity (<code>null</code> not permitted).
	 */
	public void add(ChartEntity entity) {
		if (entity == null) {
			throw new IllegalArgumentException("Null 'entity' argument.");
		}
		this.entities.add(entity);
	}

	/**
	 * Adds all the entities from the specified collection.
	 * 
	 * @param collection
	 *            the collection of entities (<code>null</code> not permitted).
	 */
	public void addAll(EntityCollection collection) {
		this.entities.addAll(collection.getEntities());
	}

	/**
	 * Returns the last entity in the list with an area that encloses the
	 * specified coordinates, or <code>null</code> if there is no such entity.
	 * 
	 * @param x
	 *            the x coordinate.
	 * @param y
	 *            the y coordinate.
	 * 
	 * @return The entity (possibly <code>null</code>).
	 */
	public ChartEntity getEntity(double x, double y) {
		int entityCount = this.entities.size();
		for (int i = entityCount - 1; i >= 0; i--) {
			ChartEntity entity = (ChartEntity) this.entities.get(i);
			if (entity.getArea().contains(x, y)) {
				return entity;
			}
		}
		return null;
	}

	/**
	 * Returns the entities in an unmodifiable collection.
	 * 
	 * @return The entities.
	 */
	public Collection getEntities() {
		return Collections.unmodifiableCollection(this.entities);
	}

	/**
	 * Returns an iterator for the entities in the collection.
	 * 
	 * @return An iterator.
	 */
	public Iterator iterator() {
		return this.entities.iterator();
	}

}
